MILWAUKEE, WI – Back in July of 2011, Derek Walker was struggling to breathe while in the back of a Milwaukee police vehicle and pleaded with cops to help him. But cops did noting to aide the man whom they arrested on suspicion of robbery.

He died in the car minutes later.

The Milwaukee Journal-Sentinel reports that it took ten months of negotiations and requests to secure the dashcam video of Walker’s final moments. The newspaper published the video on their website on Sept. 23.

City officials from the fire, police and prosecutors offices reviewed the video months ago and determined the cops did nothing wrong. Walker’s death was ruled a natural death until a Journal-Sentinel investigation prompted the medical examiner’s office to change that ruling to a homicide.

At a news conference last week, Milwaukee Police Chief Edward Flynn said the officers “missed signals that Williams was in distress.” Chief Flynn said Walker’s death was a result of a training issue.